1. Field of the Invention
The present invention relates to a semiconductor wafer testing apparatus, and more particularly, to a wireless interface probe card capable of performing a high speed one-shot wafer test of a semiconductor wafer at high speed using wireless data communication, and a semiconductor testing apparatus having the same.
2. Description of the Related Art
In general, a semiconductor device is created through a series of semiconductor manufacturing steps, including those of manufacturing a semiconductor wafer, manufacturing unit semiconductor chips on the semiconductor wafer, electrically testing a semiconductor chip to determine whether the semiconductor chip is defective (e.g., electrical die sorting (EDS) test), packaging test-passed semiconductor chips, and finally, testing packaged semiconductor chips. The EDS test is to determine whether the semiconductor chip formed on the wafer is electrically good or defective using a testing apparatus that determines defectiveness by applying an electrical signal to the semiconductor chip on the wafer.
The testing apparatus includes a tester to generate an electric signal and a probe card. A plurality of pads are arranged on each of the semiconductor chips of the semiconductor wafer. The probe card includes a plurality of needles so that the needles contact the pads. The probe card transfers a test signal generated by the tester to the semiconductor chips on the wafer via the needles contacting the pads of the wafer. The probe may also transfer the electric signal from the semiconductor chips on the wafer to the tester.
FIG. 1A is a plan view of a conventional probe card 10. FIG. 1B is a cross-sectional view of the probe card 10 of FIG. 1A. Referring to FIGS. 1A and 1B, the probe card 10 includes a printed circuit board (PCB) 20 having a through hole 25 at the central portion thereof and a plurality of needles 30 attached to the bottom surface of the PCB 20. The needles 30 are supported by a support member 40.
When the EDS test is performed for a semiconductor wafer 50 using the probe card 10, the needles 30 of the probe card 10 and a plurality of pads 65 of a semiconductor chip 60 on the wafer 50 mounted on a wafer stage 70 contact each other. A tester (not shown) transmits a test signal to the semiconductor chip 60 of the semiconductor wafer 50 via the probe card 10 and receives an electric characteristic signal from the semiconductor chip 60 via the probe card 10. Thus, the tester determines the defectiveness of the semiconductor chip 60 based on the electric characteristic signal provided by the semiconductor chip 60.
However, when the PCB 20 is stacked in multiple layers, the probe card 10 is unable to transmit a high frequency signal over 1 GHz due to signal integrity and power integrity. Also, the needles 30 need to be attached to the PCB 20 corresponding to the number of the pads 65 of the semiconductor chip 60. When a one-shot test is performed, the number of pads of the semiconductor chip 60 must be identical to that of the needles 30 of the probe card 10. But as the size of a wafer increases, performing the one-shot test is difficult or impossible.
In order to enable the one-shot test of a large-size wafer, the number of the needles 30 of the probe card 10 needs to be increased, which makes manufacture of the probe card 10 difficult. Also, as the number of the needles 30 of the probe card 10 increases, pitch of the needles 30 decreases so that short-circuits are formed between the needles 30, thereby making it difficult to accurately determine the defectiveness of the semiconductor chip 60.
In addition, since the probe card 10 physically contacts a performance board (not shown), the probe card 10 or the semiconductor wafer 50 may be damaged due to stress occurring when the probe card 10 contacts the performance board. Also, a difference in the coefficient of thermal expansion (CTE) between the semiconductor wafer 50 and the probe card 10 causes defective contacts between the pads 65 of the semiconductor wafer 50 and the needles 30 of the probe card 10.